Tandem Reactor System Having an Injectively-Mixed Backmixing Reaction Chamber, Tubular-Reactor, and Axially Movable Interface

ABSTRACT

A reactor system for gas phase reacting of at least two fluid feed streams, where the reactor system has an injectively-mixed backmixing reaction chamber in fluid communication with a tubular-flow reactor. The injectively-mixed backmixing reaction chamber has a bulkhead that slides during real-time operation to either diminish or expand the internal volume of the backmixing reaction chamber. In one embodiment, the effective passageway space through the bulkhead is also variably adjustable. In another embodiment, the tubular-flow reactor shares the bulkhead so that axial bulkhead movement commensurately expands one reaction space while diminishing the other reaction space. Input gas streams enter the backmixing reaction chamber with sufficient velocity to turbulently agitate the contents of the injectively-mixed backmixing reaction chamber by injective intermixing of the alkane-containing gas feed stream and the oxygen-containing gas feed stream. A focal application is for direct (partial) oxidative conversion of natural gas to alkyl oxygenates.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 11/526,824, filed Sep. 25, 2006, U.S. patentapplication Ser. No. 11/446,371, filed on Jun. 2, 2006, U.S. patentapplication Ser. No. 11/432,692, filed on May 11, 2006, and U.S. patentapplication Ser. No. 11/351,532, filed on Feb. 10, 2006. U.S. patentapplication Ser. Nos. 11/526,824, 11/446,371, 11/432,692, and 11/351,532are continuation-in-part applications of U.S. patent application Ser.No. 11/319,093, filed on Dec. 27, 2005 which is a continuation-in-partapplication of U.S. patent application Ser. No. 10/901,717, filed onJul. 29, 2004. The disclosures of the above applications areincorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for reacting two gaseousfluid streams (for example, without limitation, natural gas and oxidantunder conditions to optimize the formation of desired alkyl oxygenatessuch as methanol). More specifically, the embodiments relate to areactor system enabling individuated control of a primary free-radicalinduction sub-reaction separately from subsequent sub-reactions thatrespond to the induced free radicals. A focal area of application forsuch a reactor system relates to direct oxidation (under partialoxidation conditions) conversion of a C₁-C₄ alkane and oxygen into analkyl oxygenate, and, more particularly, of methane into methanol wherean initial set of methyl free radicals are first generated thatsubsequently promote a substantial series of derived kinetic stepsub-reactions.

The current industrial practice for methanol production is a two-step,Fischer-Tropsch type chemical process. The first step is the endothermicreforming of methane from natural gas to carbon monoxide and hydrogen,followed by a second step consisting of a solid-catalyzed reactionbetween carbon monoxide and hydrogen to form methanol. This technologyis energy intensive and the process economics are unfavorable for allbut very large scale methanol plants.

Various methods and apparatuses for the conversion of methane intomethanol are known. It is known to carry out a vapor-phase conversion ofmethane into a synthesis gas (mixture of CO and H₂) with its subsequentcatalytic conversion into methanol as disclosed, for example, inKaravaev M. M., Leonov B. E., et al “Technology of Synthetic Methanol”,Moscow, “Chemistry” 1984, pages 72-125. However, in order to realizethis process it is necessary to provide complicated equipment, tosatisfy high requirements for the purity of the gas, to spend highquantities of energy for obtaining the synthesis gas and for itspurification, and to have a significant number of intermittent stagesfrom the process. Also, for medium and small enterprises with thecapacity of less than 2,000 tons/day it is not economically feasible.

Russian Patent No. 2,162,460 includes a source of hydrocarbon-containinggas, a compressor and a heater for compression and heating of the gas,and a source of oxygen-containing gas with a compressor. It furtherincludes successively arranged reactors with alternating mixing andreaction zones and a means to supply the hydrocarbon-containing gas intoa first mixing zone of the reactor and the oxygen-containing gas intoeach mixing zone, a recuperative heat exchanger for cooling of thereaction mixture through a wall by a stream of coldhydrocarbon-containing gas of the heated hydrocarbon-containing gas intoa heater, a cooler-condenser, a partial condenser for separation ofwaste gases and liquid products with a subsequent separation ofmethanol, a pipeline for supply of the waste gas into the initialhydrocarbon-containing gas, and a pipeline for supply of wasteoxygen-containing products into the first mixing zone of the reactor.

In this apparatus, however, fast withdrawal of heat from the highlyexothermic oxidation reaction of the hydrocarbon-containing gas in notachievable because of the inherent limitations of the heat exchanger.This leads to the need for reduction in the quantity of suppliedhydrocarbon-containing gas and, further, it reduces the degree ofconversion of the hydrocarbon-containing gas. Moreover, even with theuse of oxygen as an oxidizer, it is not possible to provide an efficientrecirculation of the hydrocarbon-containing gas due to the rapidincrease of the concentration of carbon oxides. A significant part ofthe supplied oxygen is wasted for oxidation of CO into CO₂, and therebyadditionally reduces the degree of conversion of the initialhydrocarbon-containing gas to useful products and provides a furtheroverheating of the reaction mixture. The apparatus also requires burningan additional quantity of the initial hydrocarbon-containing gas inorder to provide the utility needs of a rectification of liquidproducts. Since it is necessary to cool the gas-liquid mixture aftereach reactor for separation of liquid products and subsequent heatingbefore a next reactor, the apparatus is substantially complicated andthe number of units is increased.

A further method and apparatus for producing methanol is disclosed inthe patent document RU 2,200,731, in which compressed heatedhydrocarbon-containing gas and compressed oxygen-containing gas areintroduced into mixing zones of successively arranged reactors, and thereaction is performed with a controlled heat pick-up by cooling of thereaction mixture with water condensate so that steam is obtained, and adegree of cooling of the reaction mixture is regulated by parameters ofescaping steam, which is used in liquid product rectification stage.

Other patent documents such as U.S. Pat. Nos. 2,196,188; 2,722,553;4,152,407; 4,243,613; 4,530,826; 5,177,279; 5,959,168 and InternationalPublication WO 96/06901 disclose further solutions for transformation ofhydrocarbons.

There is also a need for a one step process that is also suitable forsmall-scale processing, overcoming process scale limitations of theFischer Tropsch method, and also making “stranded gas” a valuablecommodity. This approach makes use of a homogeneous, gas phase partialoxidation reaction, carried out by contacting natural gas and anoxidant, with the oxidant as the limiting reagent. The most abundantproducts are methanol and formaldehyde, coming from methane, theprincipal component of natural gas. Smaller amounts of ethanol and otheroxygenated organic compounds are formed by oxidation of ethane, propane,and higher hydrocarbons that are all minor constituents of natural gas.These reaction products are all liquids, and are transportable to acentral location for separation and/or subsequent use as fuels or aschemical intermediates. A central feature of such processes is that theprocess chemistry can be executed in the field at remote locations.

U.S. Pat. No. 4,618,732 (“Direct conversion of natural gas to methanolby controlled oxidation” to Gesser, et al.) describes a process forconverting natural gas to methanol. The selectivity for methanol isindicated as resulting from careful premixing of methane and oxygenalong with the use of glass-lined reactors to minimize interactions withthe processing equipment during the reaction. The need for mixing priorto entering a reactor for reaction initiation is indicated in thefollowing extract:

“The mixing of gases preferably takes place in a pre-mixing chamber or“cross” of relatively small volume and then pass through a shortpre-reactor section before entering the heated reaction zone. However,when mixing gases at high pressure in a relatively small volume, laminarflow often takes place with the oxygen or air forming a narrowhomogeneous stream within the general flow of natural gas. The oxygen orair has little chance of becoming dispersed throughout the reactionstream prior to reaching the reaction zone. Without wishing to be boundby theory, when this takes place it is postulated that the natural gasis oxidized initially to methanol which is further oxidized, at theperiphery of the oxygen stream, i.e. in an oxygen-rich environment, tohigher oxidation products.”

U.S. Pat. No. 4,618,732 to Gesser also emphasizes the need to keep thereaction from initiation until mixing is completed ( - - - “mixingoxygen and natural gas prior to their introduction into a reactor”).

U.S. Pat. No. 4,982,023 (“Oxidation of methane to methanol” to Han, etal.) brings forth that a plurality of reactions is occurring in thedirect oxygenation of methane to methanol. In this regard, U.S. Pat. No.4,982,023 indicates some consideration of reaction-kinetics issues inthe discussion of that patent's subject matter:

“The mechanism of methanol formation is believed to involve themethylperoxy radical (CH₃OO) which abstracts hydrogen from methane.Unfortunately, up until now, the per pass yields have been limited. Thislimited yield has been rationalized as resulting from the low reactivityof the C—H bonds in methane vis-a-vis the higher reactivity of theprimary oxygenated product, methanol, which results in selectiveformation of the deep oxidation products CO and CO₂ when attempts aremade to increase conversion.”

U.S. Pat. No. 4,982,023 also makes it clear that methane and oxygen areto be premixed prior to reaction as noted in the following extract: “ .. . natural gas and the oxygen or air are kept separate until mixed justprior to being introduced into the reactor. However, if desired, theoxygen and natural gas may be premixed and stored together prior to thereaction”.

Unfortunately, laboratory results regarding methanol selectivity andsingle pass yield for non-catalyzed direct oxygenation of methane tomethanol have not been reliably duplicated in scaling the reactiontechnology to manufacturing-sized systems. The need for an efficient andlow cost reactor system for reacting two gaseous fluid streams wherecontrol of a plurality of free-radical sub-reactions is needed continuesto prompt development.

SUMMARY

It is accordingly an object of the present invention to provide areactor system for gas phase reacting of at least two fluid feed streamsinto a product stream, where the reactor system comprises aninjectively-mixed backmixing reaction chamber in fluid communicationwith a tubular-flow reactor. The injectively-mixed backmixing reactionchamber has a backmixing reaction chamber housing, a bulkhead inslideably-sealed interface to the backmixing reaction chamber housing,an injectively-mixed backmixing reaction chamber internal volume definedby the backmixing reaction chamber housing and by the bulkhead, and ahousing portion in opposite disposition to the bulkhead. The bulkhead isslideably movable during real-time operation of the reactor system toprogress within the injectively-mixed backmixing reaction chamberhousing toward the housing portion to either commensurately diminish theinjectively-mixed backmixing reaction chamber internal volume, or,alternatively, to retract away from the housing portion to therebycommensurately expand the injectively-mixed backmixing reaction chamberinternal volume.

In one embodiment, the bulkhead has at least one passageway for fluidcommunication of product stream from the injectively-mixed backmixingreaction chamber into the tubular-flow reactor. In one aspect of this,the bulkhead provides the passageway with at least one aperture having across-sectional area, and the reactor system has a blocking componentfor variably obstructing a portion of the cross-sectional area frompassageway use during real-time operation of the reactor system. Inanother aspect, the bulkhead has at least one aperture as a firstaperture, the blocking component has at least one second aperture, thefirst aperture and the second aperture have essentially identicaldimensions, and the first aperture and the second aperture are mutuallydisposed to positionally align, in one relative positioning of thebulkhead and the blocking component, to define the passageway to have across-sectional area essentially equivalent to the cross-sectional areaof the first aperture.

In another embodiment, the tubular-flow reactor has a tubular-flowreactor internal volume defined by a tubular-flow reactor housing and bythe bulkhead. In one aspect of this, slideable movement of the bulkheadtoward the housing portion commensurately diminishes theinjectively-mixed backmixing reaction chamber internal volume whileexpanding the tubular-flow reactor internal volume, and alternativeslideable movement of the bulkhead away from the housing portioncommensurately expands the injectively-mixed backmixing reaction chamberinternal volume while diminishing the tubular-flow reactor internalvolume.

In yet another embodiment, the injectively-mixed backmixing reactionchamber has a first fluid input and a second fluid input for the reactorsystem; the injectively-mixed backmixing reaction chamber has abackmixing reaction chamber output; the tubular-flow reactor has atubular-flow reactor input in fluid communication with the backmixingreaction chamber output; the first fluid input receives a first fluidfeed stream into the injectively-mixed backmixing reaction chamber; thesecond fluid input receives a second fluid feed stream into theinjectively-mixed backmixing reaction chamber; and the injectively-mixedbackmixing reaction chamber has a space-time, respective to a combinedfeed rate of the first fluid feed stream and the second fluid feedstream, of from about 0.05 seconds to about 1.5 seconds.

In yet another embodiment, a first fluid stream in the fluid feedstreams comprises methane and a second fluid stream in the fluid feedstreams comprises oxygen. In one aspect of this, at least one alkyloxygenate (e.g., without limitation, methanol, formaldehyde, and/orethanol) is manufactured through partial oxidation reacting of a firstfluid stream (in the fluid feed streams) comprising an alkane-containinggas feed stream (containing methane, ethane, propane, and/or butane) anda second fluid stream in the fluid feed streams comprising oxygen froman oxygen-containing gas feed stream; the injectively-mixed backmixingreaction chamber has an alkane gas input, an oxygen gas input, and abackmixing reaction chamber output; the tubular-flow reactor has antubular-flow reactor input in fluid communication with the backmixingreaction chamber output; the alkane gas input receives thealkane-containing gas feed stream into the injectively-mixed backmixingreaction chamber; the oxygen gas input receives the oxygen-containinggas feed stream into the injectively-mixed backmixing reaction chamber;and the injectively-mixed backmixing reaction chamber has a space-time,respective to a combined feed rate of the alkane-containing gas feedstream and the oxygen-containing gas feed stream, sufficient forinduction of alkyl free radicals from the alkane within theinjectively-mixed backmixing reaction chamber and for providing at leasta portion of the alkyl free radicals to the tubular-flow reactor input.In one aspect of this, the alkane gas input and the oxygen gas input areconfigured to turbulently agitate the injectively-mixed backmixingreaction chamber by injective intermixing of the alkane-containing gasfeed stream and the oxygen-containing gas feed stream.

In yet another embodiment, the tubular-flow reactor has a tubular-flowreactor output, and the tubular-flow reactor has at least one coolinggas input disposed between the tubular-flow reactor input and thetubular-flow reactor output for receiving a cooling gas stream andthereby quenchably cooling the tubular-flow reactor. In one aspect, thetubular-flow reactor has an axis, and the cooling gas input is moveablealong the axis during operation of the tubular-flow reactor.

In yet other embodiments, the injectively-mixed backmixing reactionchamber has an internal volume defined in part by a cylindrical surfacehaving an injectively-mixed backmixing reaction chamber axis, and onefeed stream of the feed streams is input into the internal volume from aplurality of apertures disposed along the axis and in non-parallelorientation to the axis.

In yet another embodiment, the injectively-mixed backmixing reactionchamber has an internal flow diverter defined by a conical surfacehaving an axis, the diverter defines a conical base at one end of theaxis, the conical surface defines an apexial end at the other end of theaxis, the axis of the diverter is aligned with the axis of theinjectively-mixed backmixing reaction chamber, the diverter is disposedwithin the housing such that the backmixing reaction chamber output ismore proximate to the apexial end than to the conical base, and one feedstream of the feed streams is input into the internal flow space from aplurality of apertures disposed along the injectively-mixed backmixingreaction chamber axis and in non-parallel orientation to theinjectively-mixed backmixing reaction chamber axis.

In yet another embodiment, the bulkhead has at least one passageway forfluid communication of an injectively-mixed backmixing reaction chamberproduct stream from the injectively-mixed backmixing reaction chamberinto the tubular-flow reactor, the tubular-flow reactor has atubular-flow reactor input in fluid communication with the backmixingreaction chamber output, the bulkhead provides the passageway with atleast one aperture having a cross-sectional area, the tubular-flowreactor housing has an axis and a first portion and a second portion inthreaded attachment to the backmixing reaction chamber housing, and thereactor system further comprises: a blocking component for variablyobstructing a portion of the cross-sectional area from passageway useduring real-time operation of the reactor system; and avariable-position cooling gas input disposed in the second portion inspiral orientation along the axis for quenchably cooling thetubular-flow reactor with a cooling gas stream; where the tubular-flowreactor housing second portion is in threaded attachment to thebackmixing reaction chamber housing with threads that move the secondportion along the axis when the second portion is rotated, and rotationof the second portion simultaneously repositions the bulkhead along theaxis, the cooling gas input along the axis, and the blocking componentto modify the cross-sectional area.

The novel features that are considered as characteristic for the presentinvention are set forth in particular in the appended claims. Theinvention itself, both as to its construction and its method ofoperation together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a system of an apparatus for producing alkyloxygenate (e.g., without limitation, methanol) in accordance with thepresent teachings;

FIGS. 2 and 3 are views illustrating concentrations of oxygen,formaldehyde, and methanol during reactions in accordance with the priorart and in accordance with the present invention correspondingly;

FIG. 4 represents a graph depicting the yield oxygenates of the systemas a function of recycle ratio;

FIG. 5 represents an alternate C₁-C₄ alkane to alkyl oxygenate plantaccording to the teachings of the present invention;

FIG. 6 represents an optional oxygen producing plant shown in FIG. 5;

FIG. 7 depicts a gas processing portion of the plant shown in FIG. 5;

FIG. 8 represents the liquid processing portion of the plant shown inFIG. 5;

FIG. 9 represents another alternate C₁-C₄ alkane (e.g., withoutlimitation, methane) to alkyl oxygenate (e.g., without limitation,methanol) plant according to the teachings of the present invention;

FIG. 10 represents yet another alternate C₁-C₄ alkane (e.g., withoutlimitation, methane) to alkyl oxygenate (e.g., without limitation,methanol) plant according to the teachings of the present invention;

FIG. 11 represents yet another alternate C₁-C₄ alkane (e.g., withoutlimitation, methane) to alkyl oxygenate (e.g., without limitation,methanol) plant according to the teachings of the present invention;

FIG. 12 presents a cross section simplified view of one embodiment of areactor system having an injectively-mixed backmixing reaction chamberin close coupling to a tubular-flow reactor;

FIGS. 13A and 13B present cross section simplified views of details inmodifying the internal volume of the injectively-mixed backmixingreaction chamber of FIG. 12;

FIG. 14A presents a cross section simplified view of an alternativedesign for the injectively-mixed backmixing reaction chamber of FIG. 12;

FIG. 14B shows a view of the injectively-mixed backmixing reactionchamber of FIG. 12 with a modified internal volume from that shown inFIG. 12;

FIGS. 15A and 15B present a cross section simplified view of a“hairbrush” fluid delivery insert for the injectively-mixed backmixingreaction chamber of the reactor system embodiments of FIGS. 12 and 20;

FIG. 16 presents a cross section simplified view of internal fluidpassageways for the conical fluid delivery insert for theinjectively-mixed backmixing reaction chamber of the reactor systemembodiments of FIGS. 12 and 20;

FIGS. 17A and 17B present a cross section simplified view of baffledetails and positioning at the interface between the injectively-mixedbackmixing reaction chamber and the tubular-flow reactor of the reactorsystem embodiments of FIGS. 12 and 20;

FIGS. 18A and 18B present a cross section simplified view of details andpositioning for one variable position quenching inlet of the reactorsystem embodiments of FIGS. 12 and 20;

FIGS. 19A and 19B present a series of temperature profiles for thetubular-flow reactor of the reactor system embodiments of FIGS. 12 and20;

FIG. 20 presents a cross section simplified view of an alternativeembodiment of a reactor system having an injectively-mixed backmixingreaction chamber in close coupling to a tubular-flow reactor;

FIG. 21 presents bulkhead/baffle details for an embodiment of theinterface between the injectively-mixed backmixing reaction chamber andthe tubular-flow reactor of the reactor system embodiments of FIGS. 12and 20;

FIGS. 22A-22C show axial positioning detail for the interface betweenthe injectively-mixed backmixing reaction chamber and the tubular-flowreactor of the FIG. 20 reactor system embodiment;

FIG. 23 show further detail in the quenching inlet for the FIG. 20reactor system embodiment;

FIGS. 24A and 24B show axial view detail for the FIG. 20 reactor systemembodiment; and

FIGS. 25A and 25B show views of tubular-flow reactor systems havinginjectively-mixed entry zones, multi-position quenching, andmulti-position temperature sensing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following definitions and non-limiting guidelines must be consideredin reviewing the description of this invention set forth herein.

The headings (such as “Introduction” and “Summary”) and sub-headings(such as “Amplification”) used herein are intended only for generalorganization of topics within the disclosure of the invention, and arenot intended to limit the disclosure of the invention or any aspectthereof. In particular, subject matter disclosed in the “Introduction”may include aspects of technology within the scope of the invention, andmay not constitute a recitation of prior art. Subject matter disclosedin the “Summary” is not an exhaustive or complete disclosure of theentire scope of the invention or any embodiments thereof.

The citation of references herein does not constitute an admission thatthose references are prior art or have any relevance to thepatentability of the invention disclosed herein. All references cited inthe Description section of this specification are hereby incorporated byreference in their entirety.

The description and specific examples, while indicating embodiments ofthe invention, are intended for purposes of illustration only and arenot intended to limit the scope of the invention. Moreover, recitationof multiple embodiments having stated features is not intended toexclude other embodiments having additional features, or otherembodiments incorporating different combinations the stated of features.

As used herein, the words “preferred” and “preferably” refer toembodiments of the invention that afford certain benefits, under certaincircumstances. However, other embodiments may also be preferred, underthe same or other circumstances. Furthermore, the recitation of one ormore preferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the invention.

As used herein, the word “include,” and its variants, is intended to benon-limiting, such that recitation of items in a list is not to theexclusion of other like items that may also be useful in compositions,materials, devices, and methods of this invention.

The examples and other embodiments described herein are exemplary andnot intended to be limiting in describing the full scope of compositionsand methods of this invention. Equivalent changes, modifications andvariations of specific embodiments, materials, compositions and methodsmay be made within the scope of the present invention, withsubstantially similar results.

The embodiments relate to direct oxygenation conversion of at least oneC₁-C₄ alkane into as least one alkyl oxygenate. The direct oxygenationconversion of methane into methanol is a focal conversion goal of thetechnology.

One apparatus for producing methanol in accordance with the presentinvention has a reactor 100 facilitating a gas phase oxidation of ahydrocarbon-containing gas as shown in FIG. 1. In overview of reactor100, a heated hydrocarbon-containing gas stream (from valve 120 andheater 136) and an oxygen-containing gas from line 29 are introducedinto reactor 100. As explained in detail below, the oxygen-containinggas preferably has greater than 80% oxygen content to reduce theaccumulation of inert gases by the recycling process.

The reactor 100 further optionally receives a quenching coldhydrocarbon-containing gas stream from valve 120 and heat exchanger 121for reducing the temperature of reaction during operation of theapparatus.

The apparatus has a device 114 for cooling the reaction product streammixture before separation. Additionally, partial condenser 122incorporates a gas-liquid heat exchanger to further reduce thetemperature of the products. The condenser 122 separates H₂O andalcohols from a hydrocarbon-CO₂ mixture. The partial condenser 122 ispreferably isobaric, as opposed to isothermal, to avoid pressure losses.The reaction product stream enters, and a liquid stream and gaseousstream exit condenser 122.

Block 139 represents equipment that is configured to separatecontaminants and products from a hydrocarbon-containing recycle gascomponent. In this regard, the equipment 139 is configured to remove CO₂from the reduced product stream. The equipment 139 can take the form ofa purge valve, absorber, membrane separator, or an adsorber. It isenvisioned the equipment 139 can be used to regulate the percentage ofother non-reactive components such as N₂ with, for example, a purgevalve.

In the event the system is configured to recover formaldehyde, thegaseous reduced product stream leaves the isobaric condenser 122 and ispassed to the scrubber 134. Other potential methods that can be utilizeduse materials such as various amines known to remove CO₂ andformaldehyde.

To fulfill the minimum absorption requirements, modification of the flowrate of methanol or operating temperature of the scrubber column can beused. If it is desirable to operate at extremely low absorbent flowrates, then a lower temperature can be utilized, for example 0° C. If itis desirable to operate at ambient temperatures or temperaturesachievable via cooling water, then a high flow rate can be utilized, forexample, ten times that of the flow rate for 0° C. In either scenario,the pregnant methanol absorbent stream 14 is completely regenerated bythe formaldehyde distillation column 138. Optionally, the stream 14 fromthe scrubber 134 can be passed through the condenser 122 to providecooling of the product stream and preheating of the methanol recycle toimprove the energy efficiency of the formaldehyde distillation column138.

The reactor 100 is connected with a compressor 124 and heater 126 forsupply of compressed and heated oxygen-containing gas. The rawhydrocarbon-containing gas is mixed with cleaned hydrocarbon gas fromthe scrubber 134 and is heated using a heater 136. In the event the rawhydrocarbons have a high CO₂ content, the raw hydrocarbons can be mixedwith the reduced product hydrocarbon stream from the condenser 122 priorto the entry of the scrubber 134 for removal of contaminant gases priorto entering the reactor.

The apparatus further has a unit for rectification of methanol thatincludes a flash drum 132, rectification column 128, and a vessel 130from which methanol is supplied to storage or further processing. Thisrectification column 128 is used to separate methanol (light-keycomponent) from ethanol (heavy-key component) and water (non-keycomponent). As before, it is desirable for a portion of the heavy keycomponent to enter the distillate stream (as dictated by commercialspecification for formalin). For methanol rectification, 99% or higherpurity is typical, and 99.999% is achievable with multiple columns.Stream 4 enters the column and the distillate, stream 5, and bottoms,stream 8, exit the column in liquid phase. Stream 8 has some amount ofethanol (and perhaps methanol, if ultra pure methanol was produced) andwill be used as the basis of the aqueous makeup of the commercialformalin stream (stream 11 and formalin storage 191). In this manner,some of the ethanol is recovered before the remainder is discarded inthe liquid waste stream.

Disposed between the column 128 and the condenser 122 is a flash drum132 for removal of CO₂ and formaldehyde from the liquid product stream.The purpose of the flash drum 132 is to drop the pressure to anappropriate level before entry into the methanol rectification column128 and to substantially remove any dissolved gases, typically CO₂ andformaldehyde, from the liquid product stream.

In operation, the raw hydrocarbon-containing gas stream with a methanecontent for example up to 98% and the reduced hydrocarbon product streamare supplied from an installation for preparation of gas or any othersource to the heater 136, in which it is heated to temperature 430-470°C. The heated hydrocarbon-containing gas is then supplied into reactor100. Compressed air with pressure, for example, of 7-8 MPa and with aratio 80% to 100% and, preferably, 90% to 95% oxygen is supplied by thecompressor 124 also into reactor 100. Oxidation reaction of methane tomethanol and/or formaldehyde takes place in reactor 100. Between 2% and3% O₂ of the total volume of the reactants are reacted with the heatedhydrocarbon-containing gas stream as previously described. To limit theamount of N₂ within the system, for example to less than 30%-40%, orreduce the requisite size of the purge stream to achieve the same, theO₂ stream is preferably substantially pure, thus limiting the amount ofN₂ entering the system.

An optional second stream of cold (or, in other words, a lowertemperature coolant than the gases) coolant in the reactor is suppliedinto reactor 100 as previously outlined. This stream is regulated by theregulating device (valve) 120, that can be formed as a known gas supplyregulating device, regulating valve, or the like. This cold stream canbe, for example, composed of a raw hydrocarbon stream, a recycledstream, or a portion or combination of the two. The regulator isconfigured to adjust the volume or pressure of coldhydrocarbon-containing gas based on system parameters such as, but notlimited to, pressure, temperature, or reaction product percentages at alocation further down-stream in the system.

The coolant, which is supplied from a coolant source, functions toreduce the temperature of the partially oxidized methane to reduce thecontinued oxidation or decomposition of formaldehyde. This coolant canbe any material that can easily be separated from the reaction productstream. For example, as better described below, the coolant can be anunheated hydrocarbon or methane containing gas stream.

Preferably, the coolant can be any non-oxidizing material easilyseparated from the reaction products. In this regard, the coolant can begaseous, an aerosol, or misted liquid of, for example, CO₂,formaldehyde, methanol, water, and/or steam. It is additionallyenvisioned that the coolant can further be a mixture of recycledreaction products, water, steam, and/or raw hydrocarbon gases.

Depending on the intended mode of operation of the apparatus, inparticular the intended production of methanol or methanol andformaldehyde, the reaction mixture is subjected to the reaction in thereactor without the introduction of the cold hydrocarbon-containing gasif it is desired to essentially/exclusively produce methanol. Theintroduction of the cold hydrocarbon-containing gas is used whenmethanol and formaldehyde are both desired as products. By introductionof the cold hydrocarbon-containing gas, the temperature of the reactionis reduced, for example by 30-90° Celsius, so as to preserve the contentof formaldehyde in the separated mixture by reducing the decompositionof the formaldehyde into CO₂.

The reaction mixture is supplied into the heat exchanger 114 fortransfer of heat to the reactor input stream from the reaction mixtureexiting the reactor, and, after further cooling, is supplied to partialcondenser 122. Separation of the mixture into high and low volatilitycomponents (dry gas and raw liquid, respectively) is performed in thepartial condenser 122 that may absorb at least some of the formaldehydeinto the raw liquid stream as desired. The dry gas is forwarded to ascrubber 134, while the raw liquids from the condenser 122 are suppliedto the flash drum 132.

Scrubber 134 functions to remove the CO₂ and formaldehyde from the drygas stream. In this regard, the scrubber 134 uses both H₂O and methanolat between 7-8 MPa pressure and between about 0° C. and about 50° C. toabsorb CO₂ and formaldehyde. Once the CO₂ and formaldehyde are removed,the reduced stream of hydrocarbon gas is recycled by mixing the reducedstream with the raw hydrocarbon-containing gas stream either before orwithin the reactor, as desired. The raw hydrocarbon and reduced streams,individually or in combination, are then inputted into reaction chamber100 at after being heated by heat exchanger 116 and heater 136 aspreviously described.

Rectification column 138 is used to separate carbon dioxide (non-keycomponent) and formaldehyde (light-key component) from methanol(heavy-key component) and water (non-key component). The pregnantmethanol steam, stream 14, enters rectification column 138 and isseparated into formaldehyde distillate stream 16 and bottoms stream 15.Some amount of methanol in the distillate stream is desirable sincemethanol is used as a stabilizer for the production of commercial gradeformalin (6-15% alcohol stabilizer, 37% formaldehyde, and the balancebeing water). By allowing a portion of the heavy key component into thedistillate stream the separation is more easily achieved; furthermore,process losses typically experienced during absorbent regeneration aresubsequently nullified as methanol within the distillate is used forformalin production. Stream 15 is supplemented by stream 31 so as toreplace any methanol that was transferred to the distillate stream,stream 16. Combining stream 31 and stream 15 results in stream 17, whichthen returns to the scrubber 134 as regenerated methanol absorbent.Meanwhile, the formaldehyde distillate, stream 16, combines with thevapors from flash drum 132, stream 7, to form a mixture of formaldehyde,methanol, and carbon dioxide.

The formaldehyde, water, methanol and CO₂ removed by scrubber 134 arepassed to formaldehyde rectification column 138. Column 138 removesformaldehyde and CO₂ from the methanol-water stream. Small amounts ofmethanol are combined with produced methanol and are inputted into thescrubber 134 to remove additional amounts of CO₂ and formaldehyde fromthe reduced hydrocarbon stream.

Free or non-aqueous formaldehyde is allowed to remain in the gas phaseby operation of the isobaric condenser 122. The liquid methanol productstream, or raw liquids, therefore comprise methanol, ethanol, and waterinsofar as formaldehyde remains in the gaseous stream. In this case, theliquid stream exiting the isobaric condenser 122 can bypass theformaldehyde rectification portion of the process and enter the methanolrectification column after having optionally passed through the flashdrum 132.

FIGS. 2 and 3 show diagrams of the concentration of oxygen, formaldehydeand methanol in reactions without cooling and with cooling,respectively.

As can be seen from FIG. 2, approximately after 2 sec of reaction time,the oxygen is essentially completely reacted. At this moment, thereaction temperature reaches its maximum and methanol and formaldehydeare produced in their respective proportions within the reactionmixture. Methanol is a more stable product at the end of the reactionand its concentration remains substantially stable after reaching itsmaximum concentration. Formaldehyde is less stable, and therefore with atemperature increase (the temperature increases until oxygen isessentially completely consumed) its concentration somewhat reduces.

In the reaction with the cooling shown in FIG. 3, via the introductionof cold gas when the formation of methanol and formaldehyde iscompleted, the temperature of a final period of the reaction is reducedso as to inhibit the decomposition of formaldehyde.

FIG. 4 represents a graph depicting the yield of oxygenates for thesystem as a function of the fraction of hydrocarbon gas recycled. Shownis a graph depicting the use of Michigan Antrim gas having 97% CH₄ and1% N₂. In this regard, the graph shows a significant increase in overallproduct yield using the same input stream and with little increase incapital costs. As the system efficiently manages pressure and integratesprocess energy usage, energy requirements are minimized, thus increasingthe overall system economics.

FIG. 5 represents an alternate methane to methanol plant 150. The plant150 is positioned to process methane from gas being discharged fromeither a combined oil and gas field 152 or the gas field 154. The plant150, which is preferably located in close proximity to the well bore, isgenerally formed of a gas processing plant 156, a liquid processingplant 158, and an oxygen producing plant 160. Additionally associatedwith the plant 150 are waste water treatment and utility plants 162 and164.

As shown in FIG. 6, an optional oxygen producing plant 160 can be usedto assist in the regulation of the partial oxidation of the hydrocarbonstream in the reactor 100. The oxygen producing plant 160 has acompressor 161 coupled to a heat exchanger 163 which functions toprepare the compressed oxygen for injection into a plurality ofabsorbers 165. After passing through the absorbers, the produced oxygenstream is compressed and forwarded directly to the reactor 100.

With general reference to FIG. 7, the gas processing portion of theplant 156 generally functions as described above (see FIG. 1). In thisregard, the gas processing plant 156 has compressors 170 and 172 forraising the pressure of a cleaned incoming hydrocarbon stream 174. Thisstream 174 is then divided and reacted with oxygen in the reactor 100 topartially oxidize methane as described above. It is envisioned that theparameters such as time of reaction and temperature and pressure withinthe reactor can be adjusted to selectively control the amount of CO₂,H₂O, formaldehyde and methanol that are produced in the reactor 100. Thereaction products 176 from the reactor are then transferred to theliquid processing plant 158.

As shown in FIG. 8, the liquid processing plant 158 generally functionsas described above to separate the methanol and formaldehyde from thereaction product stream 176. Shown are associated distillers, blendersand flash drums that are used to separate the constituent materials ofthe reaction product stream as described in detail above. Specifically,CO₂ is removed from the reaction product stream as are methanol and, ifdesired, formaldehyde. The scrubber 134 (see FIG. 5) prevents theaccumulation of CO₂ and allows the physical capture of formaldehyde. Thescrubber 134 can utilize a mixture of methanol and water to physicallyabsorb formaldehyde and CO₂ from the hydrocarbon gas recycle loop 135.The efficiency of the scrubber 134, which can operate adequately withoutrefrigeration, is made possible due to the high operating pressure ofthe recycle loop 135. This is opposed to cryogenically low temperaturesutilized by traditional absorption processes. The gases enter thescrubber 134 as a “dirty” gas with some amount of formaldehyde and CO₂present. These components will only be present in relatively diluteamounts, so the duty of the methanol absorbent is also relatively small.

As previously mentioned, it is envisioned that the output of the reactorcan be selectively adjusted so as to minimize the amount of formaldehydebeing produced by the gas process portion of the plant 156. While theCO₂ can be vented, it is specifically envisioned that the CO₂ from thereaction products can be injected, at a predetermined distance from thewell, into the ground to increase the output of the well. In thisregard, it is envisioned that the CO₂ can be injected at any appropriatedistance from the well so as to allow for the increase of subterraneanpressures to increase the gas or oil output of the well. Additionally,it is envisioned that the CO₂ can be injected into the casement of thewellbore or in the near-wellbore zone, to increase the output of the gasor oil and gas producing well.

While shown as a land based plant, it is specifically envisioned thatthe plant 150 can be associated with an off-shore oil rig. In thisregard, the plant 150 would either be on the off-shore rig or would be apredetermined short distance from the rig, such as immediately adjacentto the off-shore rig on a floatable platform. In the case of anoff-shore rig, which is producing natural gas, it is envisioned that themethanol converted from the methane containing hydrocarbon stream wouldbe injected into a second portion of the methane containing hydrocarbonstream to improve the flow of the hydrocarbon stream from the off-shoreoil well to land. This methanol is injected to reduce the formation ofhydrates within the piping. The methanol associated with the natural gaswould then be removed from the hydrocarbon containing stream after thestream reaches the shore.

It is further envisioned that any of the other reaction products,namely, CO₂, water or methanol can be injected directly into thehydrocarbon containing subterranean formations surrounding the platformor a land-based well. Specifically, it is envisioned that methanol canbe injected into hydrate structures surrounding the well so as toincrease the output of natural gas from a natural gas producing well.

Returning briefly to FIG. 5, it is envisioned that the CO₂ can beinjected into one portion of the well while methanol or other reactionproducts can be injected into other portions of the well. In situationswhere the natural gas may be stranded or may have nitrogen contents ofgreater than 4%, facilities may be provided to manage nitrogen build-upin the recycle loop. When outputs of any particular well 152, 154 arelow, it is envisioned that a single plant 100 having a truncated processcan be used. In these situations, only portions of the facility relatedto the partial oxidation of the hydrocarbon stream and associatedfacilities to remove CO₂ will be used near the well.

Removed CO₂ can be collected, vented or reinjected into the ground.Immediately after removal of the natural gas and associated CO₂ by thescrubber, the remaining liquid products can be transported in liquidform from the well site to another location for separation offormaldehyde, methanol and water from the waste stream. In this regard,it is envisioned that a centralized liquid processing plant to finalizethe processing of the liquid processes (158) can be located at asignificant distance from the stranded natural gas locations. Thisallows for the use of a centralized liquid process facility 158. It isalso envisioned that the conditions of the reactor can be adjusted toproduce a liquid phase that contains a commercial grade of formalin.

Another process embodiment 900 is presented in FIG. 9. Air 902 is inputto compressor 934 and then cooled in heat exchanger 904 for delivery toone of nitrogen separator 906 or nitrogen separator 962. Oxygen feed isstored in tank 908 and compressed with compressor 910 for introductionas an oxygen-containing feed stream into reactor system 914 afterheating in heater 912. Alkane-containing raw feed 926 (at least oneC₁-C₄ alkane, primarily methane or natural gas) is compressed incompressor 928 and blended with scrubber 920 alkane recycle for furtherpressurization in compressor 922 and thermal cross exchange with reactorproduct stream reactor 936 in heat exchanger 930. The recycle streampreferably provides a weight percentage proportion of from about 4:5 toabout 20:21 of alkane in the alkane-containing feed stream to reactor914. In one embodiment, where scrubber 920 is pressurized to a pressureon the order of reactor system 914 (see FIGS. 12 to 24B and theaccompanying text for further detail in reactor designs for reactorsystem 914), compressor 922 can be a centrifugal blower (non-positivedisplacement compressor). After thermal cross exchange with reactorproduct stream reactor 936 in heat exchanger 930, the combined rawalkane and recycle stream is heated in heat exchanger 932 to provide analkane-containing feed stream to reactor system 914. Embodiments ofreactor system 914 are further described in FIGS. 12-24B. Scrubber 920operates to absorb carbon dioxide and alkyl oxygenates (for example,without limitation, methanol, ethanol, and formaldehyde) while providinga recycle stream for combination with fresh alkane to provide a feedstream to compressor 922. A purge at valve 924 removes non-reactiveinerts (e.g., without limitation, nitrogen) from the reactor-scrubberprocess loop to augment efficient use of reactor system 914. A coolingquench to reactor system 914 is also optionally enabled from valve 938.Liquid bottoms from scrubber 920 are forwarded to flash drum 918 whereoverhead steam 942 separates from product stream 940 (comprising forexample and without limitation, methanol, ethanol, and formaldehyde).Furnace or thermal oxidizer 916 oxidizes waste gases for discharge tothe atmosphere. Process 900 is useful for providing a liquid materialfor further processing at another location into purified alkaneoxygenates or for providing an alkane oxygenate blend useful for a fuelor other similar use where exact purity is not critical.

FIG. 10 shows another process embodiment 1000 with a front end processloop essentially similar to process 900 presented in FIG. 9, butincorporating an in-situ distillation system 1002 for separatingmethanol in steam 1004 (for absorbent in the scrubber), purified waterin stream 1006 for use in knockdown drum 1012, and generation ofpurified methanol 1008 and waste stream 1010. Knockdown drum 1012provides initial separation of liquid from the reactor product streamprior to the introduction of the remainder of the reactor product streaminto the scrubber.

FIG. 11 presents process embodiment 1100 for generating a methanolproduct stream and formaldehyde with a front end process loopessentially similar to process 900 presented in FIG. 9, butincorporating an in-situ formaldehyde distillation system 1110 andmethanol distillation system 1108 to generate methanol product stream1102. The stream from methanol distillation system 1108 coolsformaldehyde distillation system 1110 overheads to separate carbondioxide (product stream 1106) and formaldehyde (product stream 1104) inabsorber-blender 1116. A recycle stream of methanol to the scrubber isdrawn from methanol distillation system 1108 and chilled in chiller 1112to provide a high-efficiency scrubber for condensing the reactor productstream. Furnace or thermal oxidizer 1114 oxidizes a purge to removenon-reactive inerts (e.g., without limitation, nitrogen) with somealkane (methane) from the reactor-scrubber process loop and therebyaugment efficient use of the reactor.

While a traditional tubular-flow reactor can be used with any of theabove-described processes as either reactor 100 and/or reactor 914,preferred reactor embodiments are described in the discussion of FIGS.12 to 24B.

Turning now to a deeper consideration of kinetics in the reaction andfurther embodiments for providing an improved reactor system forexecuting the overall reaction for the partial oxidation of natural gasto methanol, formaldehyde, and other oxygenates, several compactproduction facilities have been described in FIGS. 1-11 that aresuitable for small, isolated natural gas sources (stranded gas). Novelreactor systems for these processes are also further described beginningwith FIG. 12 and, more specifically, as overviewed in FIGS. 12 and 20.Beginning considerations in these reactor designs derive from the natureof the overall direct oxygenation reaction itself.

In overview, the method for reaction comprises passing a mixture ofnatural gas and oxidant through a heated, continuous flow reactor systemunder conditions to optimize the formation of methanol, and tomanipulate the reactor temperature, total pressure, and fuel (e.g.,without limitation, natural gas) to oxidant ratio to control therelative amounts of reaction products. The reaction is a partialoxidation of a C₁-C₄ fuel, such as natural gas, by an oxidant, oxygen,air, or other suitable oxygen-containing compound (preferably oxygen inair or, most preferably, oxygen). The mixture contains a substantialexcess of fuel (e.g., without limitation, natural gas) to preventcomplete combustion to undesired products such as carbon dioxide andwater.

The reaction is an exothermic, branched chain reaction. Chain branchingcauses an acceleration of the reaction rate via quadratic growth ofchain carriers. Reactions of this type are characterized by an inductionperiod during which chain carrier concentrations build up to the pointwhere a very rapid rise in reaction rate and temperature occurs. Thevery rapid rise in reaction rate is because of the quadratic growth rateof chain carriers, and the very rapid rise in temperature is because ofthe increase of the rate of heat generation that accompanies thereaction rate. Complete consumption of oxidant, the limiting reagent,occurs before the fuel (e.g., without limitation, natural gas) isentirely consumed, which limits the temperature rise. The ratio ofoxidant to fuel (e.g., without limitation, natural gas) is arranged sothat the selectivity for formation of methanol is optimized.

Reaction conditions favoring the best selectivity for methanol and otheroxygenates are as follows. The composition of the reaction mixture,after combining the alkane-containing feed stream and theoxygen-containing feed stream, should be from about 1 mol % to about 10mol % oxidant, preferably from about 2 mol % to about 5 mol % oxidant,and most preferably at about 2.5 mol % oxidant. The total pressure ofthe gases in the reactor system should be in the range of from about 6MPa to about 10 MPa, preferably from about 7.5 MPa to about 9 MPa, andmost preferably at about 8 Mpa. The reactor system wall temperatureshould be in the range of from about 600 K to about 900 K, and morepreferably from about 723 K to about 823 K. The overall reactorresidence time should be in the range of from about 1 second to about 40seconds, more preferably from about 1 second to about 10 seconds, andmost preferably from about 1 second to about 2.5 seconds.

At these conditions, methanol selectivity is in the range of from about0.35 to at least 0.60 with lower selectivities for the other oxygenatesof the alkane-containing feed stream. The conversion of methane isapproximately 5 to 10%, and conversion of the other hydrocarboncomponents of the natural gas is comparable. After the reaction,separation and recycle of the unreacted hydrocarbons is performed.

For continuous operation, the fuel (e.g., a C₁-C₄ alkane or C₁-C₄alkanes such as provided in natural gas) and oxidant must be well-mixed.For this purpose a mixing chamber/reactor is supplied for boththoroughly mixing the reaction components and for also inducing thegeneration of alkyl (e.g., without limitation, methyl) free radicalsthat are then contained in the output stream from the mixing chamber. Inthis regard, the mixing chamber therefore effectively provides aninjectively-mixed backmixing reaction chamber (“backmix reactionchamber”) in a reactor system having an injectively-mixed backmixingreaction chamber in fluid communication with a tubular-flow reactor forcarrying out the overall reaction. While not falling ideally into eithera classical continuously-stirred-tank reactor model or into a classicaltubular flow reactor model, the injectively-mixed backmixing reactionchamber of the embodiments has a number of aspects that indicate anoperational character having more of a continuously stirred tank reactoror CSTR model affinity (further denoted as a continuous feed stirredtank reactor or CFSTR; and yet further denoted as a steady-state backmixflow reactor) than of a tubular or plug-flow reactor model affinity. Theinjectively-mixed backmixing reaction chamber has a space-time,respective to a combined feed rate of the alkane-containing feed streamand the oxygen-containing feed stream, of from about 0.05 seconds toabout 1.5 seconds (a preferably contemplated space-time is about 0.1seconds) so that the feeds can be effectively mixed and so that aninitial induction period for generating alkyl free radicals (e.g.,without limitation, methyl free radicals) can be accommodated before theinjectively-mixed backmixing reaction chamber product stream (methane,oxygen, and methyl free radicals) is fed to the tubular-flow reactor forfurther reaction into methanol. In a preferred embodiment, the design ofthe injectively-mixed backmixing reaction chamber enables injectiveintermixing of the C₁-C₄ alkane and oxygen-containing feed streams toturbulently agitate streams together and to effectively turbulentlyagitate the injectively-mixed backmixing reaction chamber. In thisregard, the generating of methyl free radicals is perceived to be thefirst kinetic step reaction in the set of kinetic step reactions thatachieve direct oxygenation of methane to methanol (one respective alkyloxygenate), and the use of an injectively-mixed backmixing reactionchamber prior to the tubular-flow reactor enables a degree of freedomfor independent optimization of this methyl free radical induction step.Other free radicals derived from C₂-C₄ alkanes should usually have ashorter induction period than the methyl free radical under comparableconditions. The subsequent chain branching kinetic sub-reactions(kinetic sub-reaction steps) then covert the methyl free radicals andother components of the injectively-mixed backmixing reaction chamberproduct stream to methanol and other products; these later sub-reactionsare best controlled in the tubular-flow reactor environment that hastraditionally received the admixed (but unreacted) methane (alkane) andoxygen of prior systems.

The reactor system accordingly provides several degrees of freedom(e.g., without limitation, reactor space-time, temperature, andinjective mixing as further subsequently discussed herein) foraugmenting the initial kinetic series sub-reaction(s) and also foraugmenting, with some independency from conditions augmenting theinitial kinetic series sub-reaction(s), the subsequent kinetic seriessub-reactions in the overall set of sub-reactions that combine toachieve the overall direct oxidation reaction of at least one C₁-C₄alkane into at least one respective alkyl oxygenate.

With respect to methane in the alkane-containing feed stream, theinduction of methyl free radicals in the mixing chamber/reactor (theinjectively-mixed backmixing reaction chamber) is a clear departure fromthe prior teachings of documents such as U.S. Pat. No. 4,982,023 andU.S. Pat. No. 4,618,732, both of which, as noted in the Background,indicate that the feed streams are to be only mixed prior to theirintroduction into a reactor.

The reactants are fed to the mixing chamber/reactor (theinjectively-mixed backmixing reaction chamber) in separate streams. Uponemergence from the injectively-mixed backmixing reaction chamber, thereactants are then fed to the tubular-flow reactor. The mixing must bedone thoroughly, with the goal of attaining a uniform or essentiallyuniform distribution of reactant concentration in the injectively-mixedbackmixing reaction chamber product stream. This is necessary to avoidoxidation of the desired products—methanol and other oxygenates. Suchoxidation otherwise occurs in incompletely mixed regions whererelatively high oxidant concentrations exist, with commensuratereduction of product yield. In this regard, the mixing time in theinjectively-mixed backmixing reaction chamber must be relatively briefcompared to the residence time in the tubular-flow reactor. In view ofthe overall preferred residence times for the reactor system as whole,from about 1 second to about 2.5 seconds, the residence time in theinjectively-mixed backmixing reaction chamber must be at least 0.1second. In this regard, actual turbulent intermixing of gases can beachieved in as little as 1 ms. While there are several embodiments forachieving satisfactory mixing, as will be hereinafter described, apreferred embodiment for use with the shortest residence times usesessentially opposed turbulent jets with a diverter diffuser cone havingits apex-tending side (apexial end) closest to the tubular-flow reactor.The purpose of the cone is to minimize long residence times forsub-portions of the contents of the injectively-mixed backmixingreaction chamber in view of the high reactivity of the alkyl (e.g.,methyl) free radicals.

The reactor walls must be inert in the chemical environment of thereaction. The reactor construction material must be steel, preferablystainless steel, to contain the necessary total pressure. Insofar as asteel surface diminishes methanol selectivity, the steel is preferablycoated with an inert coating, such as Teflon™, or an organic wax.Insertion of a Pyrex™ or quartz sleeve into the reactor also provides arelatively inert surface.

A flow restriction baffle is positioned in the injectively-mixedbackmixing reaction chamber output to augment pressure drop between theinjectively-mixed backmixing reaction chamber and the tubular-flowreactor and thereby achieve a desired residence time fine turningfeature (degree of freedom of control) in the injectively-mixedbackmixing reaction chamber. In a preferred embodiment, the flowrestriction baffle (bulkhead with apertures for enabling a fluidpassageway) is conveniently axially movable so that alternative bafflepositions can be deployed in custom-configuring the effective space-timein the injectively-mixed backmixing reaction chamber prior to a processrun instance or during a process run. In a preferred embodiment, theflow restriction baffle is further in close proximity to a blockingcomponent that is conveniently axially movable so that variable baffle(bulkhead) passageways can be defined by partially blocking theapertures in the baffle (bulkhead) in custom-configuring the effectivespace-time in the injectively-mixed backmixing reaction chamber prior toa process run instance or during a process run; this feature providesanother degree of freedom for operational control.

Turning now to an overview of the tubular-flow reactor, the axialposition of the temperature maximum is quite sensitive to the reactorinlet temperature, total flow rate, and reactant composition.Fluctuations in any of these quantities can cause the position of thereactor “hot spot” to move. In an extreme case, the “hot spot” can moveout of the reaction vessel and thereby adversely affect performance. Thetubular-flow reactor is therefore preferably equipped in one embodimentwith a thermocouple that can be translated axially (along the axis ofgeneral flow in the reactor) via a sliding seal. In another embodiment,a plurality of thermocouples disposed to measure the tubular-flowreactor temperature profile along the axis of flow enable temperaturemonitoring. The thermocouple set monitors the axial gas phasetemperature distribution in the reactor, and the thermocouplemeasurements are also used for control of the reactor.

The methanol, formaldehyde and other oxygenates can undergo thermaldecomposition in the high temperatures of the tubular-flow reactor,resulting in product loss. Such decomposition is minimized by cooling ofthe reactor contents at a location immediately downstream from the “hotspot”. Because wall cooling is not sufficiently responsive, a preferredembodiment employs injection of a cold gas by means of a tube whoseaxial position can also be changed by means of a sliding seal. The coldgas is preferably natural gas, but carbon dioxide, nitrogen, or anotherinert substance may also be used.

FIG. 12 presents a cross section simplified view 1200 of a reactorsystem having an injectively-mixed backmixing reaction chamber 1202 inclose coupling to a tubular-flow reactor 1204 so that a reactor systemhaving an injectively-mixed backmixing reaction chamber in fluidcommunication with a tubular-flow reactor is provided for one of theprocesses described in conjunction with FIGS. 1-11. The main chamber andreactor sections of the reactor system are aligned along axis 1220 withthe injectively-mixed backmixing reaction chamber having housing 1206(defining internal volume 1234 with a cylindrical surface inco-operation with bulkhead 1232). Tubular-flow reactor 1204 has housing1210 defining internal volume 1248 in co-operation with slideabletubular-flow reactor 1204 section having housing 1208 and with bulkhead1232. An alkane-containing gas feed stream (a first fluid stream) entersthrough alkane gas input 1222 and similar alkane gas inputs as depicted.An oxygen-containing gas feed stream (a second fluid stream) entersthrough oxygen gas input 1224 and conical diverter/distributor 1226.Conical diverter/distributor 1226 has a conical base (base 1614 of FIG.16) connected to a portion of housing 1206 in opposite disposition tobulkhead 1232. A backmixing reaction chamber output is established bybulkhead (baffle) 1232 and passageway 1270 (with its associated fluidpassageways shown in more detail in FIGS. 17A and 17B) and optionalblocking component 1230. Bulkhead (baffle) 1232 and optional (forvariable passageway definition in real-time operation of the reactorsystem) blocking component 1230 provide passageways such as passageway1270 for feeding the injectively-mixed backmixing reaction chamber 1202product stream to tubular-flow reactor 1204. Tubular-flow reactor 1204therefore has a tubular-flow reactor input in fluid communicationthrough passageway 1270 with the backmixing reaction chamber 1202 outputat bulkhead (baffle) 1232 and blocking component 1230. Alkane gas input1222 (along with similar alkane gas inputs as depicted) and oxygen gasinput 1224 with conical diverter/distributor 1226 and oxygen inputaperture 1228 (along with similar alkane gas inputs as depicted) areconfigured (positioned and sized with respect to the flows of thealkane-containing and the oxygen-containing feed streams) to turbulentlyagitate reaction components within internal volume 1234 ofinjectively-mixed backmixing reaction chamber 1202 by injectiveintermixing of the alkane-containing gas feed stream and theoxygen-containing gas feed stream.

Tubular-flow reactor 1204 has a tubular-flow reactor output 1260, andtubular-flow reactor 1204 has cooling gas input 1274 disposed betweenthe tubular-flow reactor input from passageways (passageway 1270) atbulkhead 1232 and tubular-flow reactor output 1260 for receiving acooling gas stream (that enters at cooling input port 1236 and then intocooling gas internal input port 1250 before proceeding to cooling gasinput 1274) and thereby quenchably cooling tubular-flow reactor 1204. Inthis regard, cooling gas input 1274 in one embodiment is in an elongatedtube (tube 1262) with at least one aperture 1274 (see FIGS. 18A and 18Bfor cross-sectional detail respective to axis 1220) for conveying thecooling quench flow into reactor space 1248. Tube 1262 co-operates withguide tube 1264. In one embodiment, tube 1262 rotates within guide tube1264 to regulate the amount of quench delivered to a location. In analternative embodiment, tube 1262 is axially slideable (with referenceto axis 1220) to position within tubular-flow reactor 1204 and providelocal quenching. In yet another embodiment, tube 1262 rotates withinguide tube 1264 to regulate the amount of quench delivered to a locationand also is axially slideable (with reference to axis 1220) to positionwithin tubular-flow reactor 1204 and provide local quenching. Thequenching components (including drawing references 1262, 1250, 1236,1264, and 1274) therefore provide a degree of freedom for managing thetemperature profile along axis 1220 within tubular-flow reactor 1204.Thermocouples such as thermocouple 1216 and similar thermocouples asdepicted provide measurements for the temperature profile in oneembodiment. A sliding thermocouple 1214 (with thermocouple sensor 1272and sealed with sliding seal 1212 to housing 1210) provides measurementsfor the temperature profile in another embodiment. FIG. 12 shows anembodiment having stationary thermocouples such as thermocouple 1216 waswell as a sliding thermocouple 1214 (with thermocouple head 1272).

Tubular-flow reactor 1204 has housing 1210 defining internal volume 1248in co-operation with the slideable tubular-flow reactor 1204 sectionhaving housing 1208 and also having bulkhead 1232 (with optionalblocking component 1230 for providing passageway 1270 as across-sectionally-variable passageway). Bulkhead 1232 and blockingcomponent 1230 are in slideably-sealed interface to backmixing reactionchamber housing 1206 and are therefore both effectively attached to theslideable tubular-flow reactor 1204 section having housing 1208. Housingsection 1208 is therefore in slideably-sealed interface to housing 1210and also to housing 1206 with seals 1244, 1246, and 1238 providingisolation from the external environment. Injectively-mixed backmixingreaction chamber 1202 has an injectively-mixed backmixing reactionchamber internal volume 1234 defined by backmixing reaction chamberhousing 1206 and by bulkhead 1232 (with optional blocking component1230). Bulkhead 1232 (and blocking component 1230) is thereforeslideably movable during real-time operation of the reactor system ofview 1200 to progress within backmixing reaction chamber housing 1206toward input 1224 to thereby commensurately diminish internal volume1234, and bulkhead 1232 (and blocking component 1230) is alternativelyslideably movable during real-time operation to retract away from input1224 to thereby commensurately expand internal volume 1234. In theembodiment of FIG. 12, tubular-flow reactor 1204 has a tubular-flowreactor internal volume 1248 defined by tubular-flow reactor housings1208 and 1210 and by bulkhead 1232 (with blocking component 1230).Bulkhead 1232 (and blocking component 1230) is therefore slideablymovable during real-time operation of the reactor system of view 1200 tothereby commensurately diminish internal volume 1248 when moving awayfrom toward input 1224, and bulkhead 1232 (with optional blockingcomponent 1230) is alternatively slideably movable during real-timeoperation to move toward input 1224 to thereby commensurately expandinternal volume 1248. This moveable interface enables a degree offreedom for managing relative space-time (essentially equivalent, forgaseous flow, to internal reaction volume divided by volumetric flowrate moving through that internal reaction volume) within the reactorsystem of view 1200 between both tubular-flow reactor 1204 andinjectively-mixed backmixing reaction chamber 1202.

Essentially, the functionality enabled by the features of bulkhead 1232(and blocking component 1230) is for a backmixing reaction chamber wherethe internal volume (defined by an internal surface of a housing andalso by the surface of any component in moveably sealed interface tothat internal surface) can be readily modified so that the space-time,provided by the backmixing reaction chamber to chemically reactingcompositional components in gaseous fluids flowing within the internalvolume, can be modified without necessarily modifying flow rate(s),turbulency, and/or pressure drop of those fluids. In this regard, anyapproach for modifying the internal volume from a first internal volumeto a second internal volume is potentially useful. In one conceptualizedembodiment, for instance, bulkhead 1232 is axially fixed, conicaldiverter/distributor 1226 has a base wide enough to slideably sealagainst backmixing reaction chamber housing 1206, conicaldiverter/distributor 1226 has a slideable tube (not shown)interconnecting to input 1224, and conical diverter/distributor 1226thereby commensurately diminishes internal volume 1234 when moving awayfrom input 1224 and commensurately expandes internal volume 1234 whenmoving toward input 1224. In another conceptualized embodiment, housing1206 has a movable portion that invades into the chamber to diminishinternal volume 1234 and alternatively withdraws from the chamber toincrease internal volume 1234. In yet another conceptualized embodiment,an internal diaphramed component modifies its characteristics tocommensurately modify internal volume 1234.

Seal 1246, seal 1212, seal 1244, seal 1238, seal 1242, and seal 1240 allenable slideable movement of the movable components of the reactorsystem of view 1200. Rotation component 1218 enables rotation ofblocking component 1230 during operation. As should be apparent,movement of components (especially during operation of the reactorsystem of view 1200) is preferably achieved with assistance fromvariable speed motors, levers, levers with associated gearing, and/orstep-motors and with associated gearing (not shown but that should beapparent to those of skill).

In operation, an alkane-containing feed stream and an oxygen-containingfeed stream are input to injectively-mixed backmixing reaction chamber1202 through input ports such as input 1222 (alkane-containing feedstream) and input 1224 (oxygen-containing feed stream).Injectively-mixed backmixing reaction chamber 1202 internal conditionsare managed to induce alkyl free radical formation in injectively-mixedbackmixing reaction chamber 1202 to yield an injectively-mixedbackmixing reaction chamber product stream for output and fluidcommunication into tubular-flow reactor 1204 through passageways such aspassageway 1270 in bulkhead 1232 and blocking component 1230. Thecomponents are sized and arranged to provide significant molecularmomentum in the entering fluids so that injective mixing and a turbulentreaction fluid in injectively-mixed backmixing reaction chamber 1202 areestablished. The injectively-mixed backmixing reaction chamber productstream fed to tubular-flow reactor 1204 via passageway 1270 thereforecomprises oxygen, unreacted alkane, and at least a portion of the alkylfree radicals that were induced in injectively-mixed backmixing reactionchamber 1202. In this regard, the “reaction” of alkane to alkyloxygenate (focally, the “reaction” of methane to methanol) involves alarge plurality of reactions (termed herein also as kinetic seriessub-reactions or kinetic sub-reactions); indeed, there may be at least60 kinetic series sub-reactions in the overall “reaction” of methane tomethanol and other alkyl oxygenates occurring in the system. The initialkinetic series sub-reaction occurs to induce an alkyl radical from analkane when an alkane molecule is exposed to molecular oxygen. There istherefore efficacy in handling this reaction in a separatedinjectively-mixed backmixing reaction chamber that is in fluidcommunication with a tubular-flow reactor where a consistent (with timeand at steady state operation) portion of the alkyl radicals will beessentially conveyed (fed into the tubular-flow reactor) to provide thebasis for enabling the many subsequent parallel and sequential kineticseries sub-reactions that require a heat management approach moreamenable to tubular-flow reactors than to injectively-mixed backmixingreaction chambers. Although close-coupled to a tubular-flow reactor inthe embodiments, the injectively-mixed backmixing reaction chamberprovides the reaction components with an essentially universalcompositional and physical (temperature, pressure, and molecularmomentum) operational state within its space-time compared to atubular-flow system; this enables management of the critical alkylradical induction step independently from the tubular-flow reactorwhere, along the axis of the tubular-flow reactor, the reactioncomponents have an axially (and probably radially) differentiatedcomposition and physical state.

As should be apparent to those of skill, the management of scale-up insuch a system as the reactor system of view 1200 needs to manage thechallenge of providing acceptable molecular momentum in increasingspace-time situations; if the molecular momentum diminishes, thereaction fluid in the injectively-mixed backmixing reaction chamber willmigrate toward the laminar flow range and the overall necessaryconsistency of the injectively-mixed backmixing reaction chamberreaction fluid may thereby become potentially compromised; therefore, areactor according to view 1200 appears efficacious in small-scaleprocessing for making “stranded gas” a valuable commodity.

The overall reactor system space-time, respective to a combined feedrate of the alkane-containing feed stream and the oxygen-containing feedstream, is not greater than 40 seconds, and is preferably not greaterthan 2.5 seconds. Reaction space-time for the injectively-mixedbackmixing reaction chamber is managed to be not greater than 1.5seconds.

FIGS. 13A and 13B presents cross section simplified views 1300 and 1350of details in modifying the internal volume of the injectively-mixedbackmixing reaction chamber 1202 of FIG. 12. In this regard, analternative view 1300 is presented for injectively-mixed backmixingreaction chamber 1202 in FIG. 13A where a “hairbrush” distributor 1308(further detailed in FIGS. 15A and 15B) for the oxygen-containing feedstream is depicted. View 1300 of FIG. 13A generally shows a bulkhead1304 and optional blocking component 1302 in fully expanded or extendedorientation to housing 1306.

Reactor view 1350 of FIG. 13B generally shows bulkhead 1304 and optionalblocking component 1302 in inserted orientation to housing 1306 todiminish the volume (and, in steady state operation, the space time) ofthe injectively-mixed backmixing reaction chamber respective to thevolume (space-time) of view 1300.

FIG. 14A presents a cross section simplified view 1400 of anotheralternative design for injectively-mixed backmixing reaction chamber1202 of FIG. 12. In this regard, a hemispherical head portion 1402 isprofiled for the housing, with a comparably hemispherical profile in theinserted bulkhead.

FIG. 14B shows a view 1450 depicting the injectively-mixed backmixingreaction chamber 1202 of FIG. 12 with a modified internal volume fromthat shown in FIG. 12. Bulkhead 1232 and (optional) blocking component1230 are depicted in inserted orientation to housing 1206 to diminishthe volume (and, in steady state operation, the space time) of theinjectively-mixed backmixing reaction chamber 1202 respective to thevolume (space-time) of view 1200.

FIGS. 15A and 15B present aligned cross-sectional views 1500 and 1550 ofthe “hairbrush” fluid delivery insert 1308 for an alternative design forinjectively-mixed backmixing reaction chamber 1202 of FIG. 12. Axis 1504is aligned with axis 1220 in the preferred embodiment, with view 1500showing “hairbrush” distributor 1308 detail respective to a planeperpendicular to axis 1504, and view 1550 showing “hairbrush”distributor 1308 detail respective to a plane parallel to axis 1504. Theoxygen-containing feed stream is input into internal flow space 1234from a plurality of apertures (such as aperture 1502) disposed along theinjectively-mixed backmixing reaction chamber axis in the essentialcenterline of the cylindrical surface of housing 1206 and innon-parallel orientation to the injectively-mixed backmixing reactionchamber axis 1220 when axis 1504 is essentially aligned with axis 1220.

FIG. 16 presents a cross section simplified view 1600 of internals forconical fluid delivery insert 1226 for delivering the oxygen-containingfeed stream into the injectively-mixed backmixing reaction chamber 1202of FIG. 12. The internal flow diverter is defined by a conical surface1604 having an axis 1602. A conical base 1614 is at one end of axis1602, and apexial end 1612 (an end that, if the cone were extended,would ultimately converge to provide the apex of the cone) is at theother end of axis 1602. As shown in view 1200 of FIG. 12, axis 1602 isaligned with axis 1220 of injectively-mixed backmixing reaction chamber1202 when conical diverter 1226 is disposed within cylindrical housing1206 such that the backmixing reaction chamber output (passageway 1270)is more proximate to apexial end 1612 than to conical base 1614. Theoxygen-containing feed stream is input into inlet 1610 (from inlet 1224of FIG. 12) and then into internal flow space 1234 from a plurality ofapertures 1608 disposed along injectively-mixed backmixing reactionchamber axis 1220 (axis 1602) and in non-parallel orientation to axis1220. Internal passageway 1606 fluidly conveys the oxygen-containingfeed stream to the plurality of apertures 1608.

FIGS. 17A and 17B present cross section simplified views of theinterface baffle (1232/1230) details and positioning at the interfacebetween injectively-mixed backmixing reaction chamber 1202 andtubular-flow reactor 1204 of the FIG. 12 reactor system. In view 1700 ofFIG. 17A, bulkhead 1702 has at least one aperture 1704 defining apassageway (see passageway 1270 in FIG. 12) for fluid communication ofan injectively-mixed backmixing reaction chamber product stream frominjectively-mixed backmixing reaction chamber 1202 into tubular-flowreactor 1204. Bulkhead 1702 (bulkhead 1232 in FIG. 12) provides thepassageway with at least one aperture 1704 having a cross-sectionalarea. In a flowing fluid, bulkhead 1702 with apertures 1704 defines abaffle for creating a pressure drop between injectively-mixed backmixingreaction chamber 1202 and tubular-flow reactor 1204 as the flowing fluidpasses from injectively-mixed backmixing reaction chamber 1202 intotubular-flow reactor 1204. In a “tuned” reactor system, apertures 1704can be precisely sized in one embodiment so that no blocking componentis needed; such an arrangement has fewer degrees of freedom foroperation, but also is less complex from a sealing and constructionstandpoint. For real-time operational varying of the effectivepassageway created by aperture 1704, a blocking component 1230 isdeployed in an alternative embodiment where, as shown in view 1750 ofFIG. 17B, blocking component 1230 can be rotated to “block” a portion ofthe cross-sectional area of aperture 1704 where a portion of blockingcomponent 1706 (blocking component 1230 of FIG. 12) is shownconstricting the passageway of aperture 1704 (note that view 1750 can beconceptualized as a view parallel to axis 1220 and towardinjectively-mixed backmixing reaction chamber 1202 from tubular-flowreactor 1204) and thereby restricting the passageway.

In a preferred embodiment, bulkhead (1232/1702) has at least oneaperture 1704 as a first aperture, and blocking component (1230/1706)has at least one second aperture (1708). These first and secondapertures preferably have essentially identical dimensions, and firstaperture 1704 and second aperture 1708 are mutually disposed topositionally align, in one relative positioning of bulkhead (1232/1702)and blocking component (1230/1706), to define the passageway (1270) tohave a cross-sectional area essentially equivalent to thecross-sectional area of the first aperture. In view 1750, this can beappreciated by considering that the portion of aperture 1704 that is notblocked from passageway use by blocking component 1706 is also theportion of aperture 1708 that is not blocked from passageway use bybulkhead 1702.

An alternative embodiment of the combination of bulkhead (1232/1702) andblocking component (1230/1706) that does not include use of rotationcomponent 1218 is further discussed with respect to FIG. 21. In thisalternative embodiment, bulkhead (1232/1702) is movable respective tostationary blocking component (1230/1706) where key slot 1710 providesan axially (with respect to axis 1220) slideable restraint against key2110 (FIG. 21) for prohibiting rotation of blocking component(1230/1706). In this embodiment, bulkhead (1232/1702) is firmly attachedto housing 1208, but housing 1208 further rotates about axis 1220 toachieve a variable passageway 1270 defined by aperture 1704 and aperture1708. Key 2110 is affixed to housing 1206 (details not shown), andaperture 1714 (FIG. 17A) provides a non-resistive opening for key 2110to pass into internal volume 1248 so that bulkhead (1232/1702) andblocking component (1230/1706) move axially (axis 1220) respective toinlet 1224 with blocking component 1230/1706 always restrained andbulkhead 1232/1702 always capable of rotation about axis 1220.

Ball bearings 1712 are used in preferred embodiments to augment smoothrotation of the movable component (either of bulkhead 1232/1702 orblocking component 1230/1706 depending upon their particular embodiment)against the non-movable component in the baffle system.

FIGS. 18A and 18B present cross sectional simplified views 1800, 1850,and 1860 of details and positioning for the variable position quenchinginlet 1274 for the FIG. 12 reactor system. Guide tube 1264 is shown inperpendicular cross-sectional in view 1800 respective to axis 1220 astube cross-section 1802 having an elongated slot 1808 running along axis1220. The elongated slot is difficult to show in FIG. 12, but it isdepicted in FIGS. 18A and 18B as fully open passageway 1808 to conveythe axial slot; quench tube 1804/1262 is shown with aperture1806/1274—see inlet passageway 1274 in FIG. 12—to show that it is anopening having substantially less axial dimension than the axialdimension of slot 1808 of guide tube 1802/1264. Tube 1804/1262co-operates with guide tube 1802/1264 as shown in view 1850 to notconvey quench into internal volume 1248 when aperture 1806 is rotated toblock the passageway (1274) with the internal surface of guide tube1802/1264. In one embodiment, tube 1804/1262 is axially slideable withinguide tube 1802/1264 to reposition aperture 1806/1274 axially along axis1220. View 1860 then shows rotation of radial alignment between tube1804/1262 and guide tube 1802/1264 so that passageway/inlet 1274 isenabled. Note that several alternative sets (not shown) of apertures1806 can be readily provided at different radial positions of tube 1804to provide alternative quench patterns as a function of the radialorientation of tube 1804/1262 along axis 1220 in tubular-flow reactor1204.

FIGS. 19A and 19B present a series of temperature profiles for thetubular-flow reactor of the FIG. 12 reactor system in operation. In thisregard, axis of abscissas 1904 and axis of ordinates 1906 are identicalthroughout FIGS. 19A and 19B, with axis of abscissas 1904 showingdistance along axis 1220 of tubular-flow reactor 1204 and axis ofordinates 1906 depicting temperature within the reaction fluid oftubular-flow reactor 1204. Locus 1902 (FIG. 19A) is a conceptualizeddepiction of a temperature profile for tubular-flow reactor 1204 withoutbenefit of quenching. Locus 1922 (FIG. 19B) is a conceptualizeddepiction of a temperature profile for tubular-flow reactor 1204 withbenefit of quenching at location 1938. The afore-discussed kineticseries sub-reactions will vary in their activity depending upon thetemperature profile along axis 1220 within tubular-flow reactor 1204.So, for instance, the product mix from tubular-flow reactor 1204 will bedifferent for each of Loci 1902, 1922, and 1932 per their differentiatedthermal profiles, commensurately differentiated energies, andcommensurately differentiated kinetic activity for individualsub-reactions in the kinetic series sub-reaction set. The quenching tubedesign therefore affords yet another degree of freedom for optimizingthe composition of an alkyl oxygenate reactor system product streamgenerated from a C₁-C₄ alkane-containing feed stream and anoxygen-containing feed stream.

FIG. 20 presents a cross section simplified view 2000 of an alternativeembodiment of a reactor system having an injectively-mixed backmixingreaction chamber in close coupling to a tubular-flow reactor. Theinterface baffle assembly (bulkhead 1232 and blocking component 1230assembly embodiments as described with respect to FIG. 12 and thealternative key-restrained deployment embodiments of FIGS. 17A, 17B, and21) is slideably movable and rotated during real-time operation of thereactor system of view 2000 to progress and/or retract away from input2062 by use of a threaded seal and connection facilitated by malethreading 2012 (male threading 2212 in FIGS. 21 and 22A-22C). Themajority of the injectively-mixed backmixing reaction chamber and thetubular-flow reactor share housing 2070, that is further threaded toprovide female threading for co-operating with threading 2012/2212.FIGS. 22A-22C show further detail in this regard where FIG. 22A showstubular-flow reactor sleeve 2016 in fully progressed position, FIG. 22Bshows tubular-flow reactor sleeve 2016 in mid-pointprogression/retraction position, and FIG. 22C shows tubular-flow reactorsleeve 2016 in fully retracted position.

The backmixing reaction chamber and tubular-flow reactor of the reactorsystem of view 2000 are aligned along axis 2014. An alkane-containinggas feed stream (a first fluid stream) enters through alkane gas input2060 and the plurality of alkane gas input apertures as depicted. Anoxygen-containing gas feed stream (a second fluid stream) enters throughoxygen gas input 2062 and the hairbrush distributor as previouslydiscussed with respect to FIGS. 15A and 15B. In an alternativeembodiment, a conical diverter/distributor (FIG. 16) is used for theoxygen-containing feed stream.

The tubular-flow reactor has tubular-flow reactor sleeve 2016 inslideably sealed interface at seal 2008 to housing 2004 and provides afluid output into a relatively small space defined by housing 2004.Housing 2004 has an axial depth sufficient to accommodate the full axialtraverse enabled by threading 2012/2212 (see also FIGS. 22A-22C).Housing 2004 has an output for the reactor product stream at output2020. Cooling gas input 2002 receives the previously-described coolinggas stream into cooling gas space 2072 (defined between the internalsurface of housing 2070 and the external surfaces of sleeve 2016 andblocking tube 2006). The cooling gas stream then proceeds into theinternal space of sleeve 2016 via spiral slot 2018, at a point where anaxial slot (axial slot 2032 of perpendicular cross section view 2028across axis 2014 in right-facing orientation at 2042 and of FIG. 23) ofblocking tube 2006 and spiral slot 2018 align to define a passageway(2302 of FIG. 23) and also to thereby quenchably cool the internal spaceof tubular-flow reactor sleeve 2016. Sleeve 2016 therefore co-operatesclosely with blocking tube 2006.

Sleeve 2016 is sealed to housing 2070 with slideable seal 2074 andthereby rotates to simultaneously process/regress respective to theinjectively-mixed backmixing reaction chamber per threads 2012/2212(FIGS. 22A-22C), regulate the amount of quench delivered to a locationwithin tubular-flow reactor sleeve 2016 (described with FIG. 20 andfurther described with FIG. 23), and modify the passagewaycross-sectional area (fixed-key baffle assembly as previously discussedand further discussed in FIG. 21). While these three degrees of controlfreedom (baffle positional procession/regression, quench delivery, andbaffle passageway cross-sectional area) are therefore not managed withfull independence, differences in the rate of change of each with onerotation of sleeve 2016 enables a controllable system having fewer sealsthan the embodiment described with respect to FIG. 12 and with only verylimited convolution between these three degrees of freedom for normaloperation. In this regard, one full rotation of sleeve 2016 achieves afull transfer of spiral slot 2018 position (its full axial analogrange), perhaps about 2% of the full axial analog range for bafflepositional procession/regression, and 600% of the passagewaycross-sectional area full axial analog range for a baffle having 6apertures (FIGS. 17A and 17B). Therefore, sleeve 2016 is first rotatedto position within the axial analog range for baffle positionalprocession/regression, then to position within the axial analog rangefor quenching, and finally to position within the axial analog range forthe passageway cross-sectional area. Insofar as baffle positioning isanticipated to be a relatively strategic operational setting for aparticular alkane-gas feed stream composition, real-time operationaladjustments should relate more to the single-rotation quench and (⅙rotation) baffle passageway positioning.

Perpendicular cross section view 2030 across axis 2014 in left-facingorientation at 2040 shows further detail in aperture positioning forinputting feeds from input 2060 and 2062 into the backmixing reactionchamber.

FIG. 21 presents bulkhead/baffle details 2100 for the FIG. 20 reactorsystem embodiment and also for the alternative embodiment of theinterface between the injectively-mixed backmixing reaction chamber andthe tubular-flow reactor of the FIG. 12 reactor system embodiment aspreviously referenced with respect to FIGS. 17A and 17B. Sleeve 2016 isreprised from FIG. 20 with male threading 2012/2212. As described forthe alternative embodiment respective to FIGS. 17A and 17B, blockingcomponent 2108 is restrained from rotation by key 2110 (as inserted intoslot 1710 (FIG. 17B) and bulkhead 2104 is in non-slideable attachment tosleeve 2016. Ball bearings 2106 interface bulkhead 2104 (end of sleeve2016) to blocking component 2108. Bulkhead 2104 (sleeve 2016) rotatesfreely around key 2110 by virtue of non-restraining circular aperture1714 (FIG. 17A).

As previously discussed, FIGS. 22A-22C show axial positioning details2200, 2230, and 2260 for the interface between the injectively-mixedbackmixing reaction chamber and the tubular-flow reactor of the FIG. 20reactor system embodiment. Sleeve 2016 is reprised from FIG. 20 withmale threading 2012/2212.

FIG. 23 shows further detail 2300 in the quenching inlet for the FIG. 20reactor system embodiment. In this regard, a vertical view of sleeve2016 and blocking tube 2006 in alignment with the axis of entry forinput 2002 (FIG. 20) is shown. Sleeve 2016, blocking tube 2006, spiralslot 2018, and axial slot 2032 (view 2028 of FIG. 20) are all reprisedfrom FIG. 20. Location 2302 shows the alignment point of blocking tube2006 and spiral slot 2018 for delivery of the quenching gas into sleeve2016 to thereby quenchably cool the internal space of the tubular-flowreactor.

FIGS. 24A and 24B show axial view detail for the FIG. 20 reactor systemembodiment. FIG. 24A shows a right-facing view along axis 2014 (FIG. 20)from the outside of the reactor system; inputs 2060 and 2062 arereprised from FIG. 20. FIG. 24B shows perpendicular cross section view2450 across axis 2014 in left-facing orientation at 2022 (FIG. 20);input 2002 is reprised from FIG. 20 and apertures 1704/1706 are reprisedfrom FIGS. 17A and 17B.

FIGS. 25A and 25B show views 2500 and 2550 of two tubular-flow reactorsystem embodiments having injectively-mixed entry zones (zone 2520 inboth of FIGS. 25A & B), multi-position quenching, and multi-positiontemperature sensing. Mixing zone 2520 in both FIG. 25A and FIG. 25Bshows a symbolic conical distributor diverter 2502 with a full cone,highly similar to the conical diverter of FIG. 16 and also of FIG. 12.System view 2500 of FIG. 25A shows multiple thermocouples (such asthermocouple 2510) and multiple quench inlet ports (such as quench inletport 2508) in housing 2512. System view 2550 of FIG. 25B shows variableposition thermocouple 2504 and a variable position thermocouple quenchinlet port 2506 sealing disposed within the internal space defined byhousing 2514. Quenching and temperature measurement are therefore highlysimilar in FIG. 12 and FIGS. 25B for the tubular-flow reactors of bothof these embodiments. The systems of both FIG. 25A and FIG. 25B areuseful in providing reactor systems that are highly similar to theembodiments of FIGS. 12 and 20 except for the absence in FIGS. 25A and25B of a separating baffle assembly defining a clear interface betweenan injectively-mixed backmix reaction chamber and the tubular-reactor.In this regard, data from operation of a system of either of FIG. 25A orFIG. 25B, when compared to data from operation of a system of either ofFIG. 12 or FIG. 20, has value in indicating efficacy for settingsrespective to the baffled interface (bulkhead 1232/component 1230 inFIG. 12 or the threaded baffling assembly of FIG. 20).

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofmethods and constructions differing from the types described above.While the invention has been illustrated and described as embodied inthe method of and apparatus for producing methanol, it is not intendedto be limited to the details shown, since various modifications andstructural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

1. A reactor system for gas phase reacting of at least two fluid feedstreams into a product stream, said reactor system comprising: aninjectively-mixed backmixing reaction chamber in fluid communicationwith a tubular-flow reactor, said injectively-mixed backmixing reactionchamber having a backmixing reaction chamber housing; and a bulkhead inslideably-sealed interface to said backmixing reaction chamber housing;wherein said injectively-mixed backmixing reaction chamber has aninjectively-mixed backmixing reaction chamber internal volume defined bysaid backmixing reaction chamber housing and by said bulkhead; saidbackmixing reaction chamber housing has a housing portion in oppositedisposition to said bulkhead; and said bulkhead is slideably movableduring real-time operation of said reactor system to progress withinsaid injectively-mixed backmixing reaction chamber housing toward saidhousing portion to thereby commensurately diminish saidinjectively-mixed backmixing reaction chamber internal volume, and saidbulkhead is alternatively slideably movable during real-time operationof said reactor system within said injectively-mixed backmixing reactionchamber housing to retract away from said housing portion to therebycommensurately expand said injectively-mixed backmixing reaction chamberinternal volume.
 2. The reactor system of claim 1 wherein said bulkheadhas at least one passageway for fluid communication of aninjectively-mixed backmixing reaction chamber product stream from saidinjectively-mixed backmixing reaction chamber into said tubular-flowreactor.
 3. The reactor system of claim 2 wherein said bulkhead providessaid passageway with at least one aperture having a cross-sectionalarea, and said reactor system has a blocking component for variablyobstructing a portion of said cross-sectional area from passageway useduring real-time operation of said reactor system.
 4. The reactor systemof claim 3 wherein said bulkhead has at least one said aperture as afirst aperture, said blocking component has at least one secondaperture, said first aperture and said second aperture have essentiallyidentical dimensions, and said first aperture and said second apertureare mutually disposed to positionally align, in one relative positioningof said bulkhead and said blocking component, to define said passagewayto have a cross-sectional area essentially equivalent to saidcross-sectional area of said first aperture.
 5. The reactor system ofclaim 1 wherein said tubular-flow reactor has a tubular-flow reactorinternal volume defined by a tubular-flow reactor housing and by saidbulkhead.
 6. The reactor system of claim 5 wherein slideable movement ofsaid bulkhead toward said housing portion commensurately diminishes saidinjectively-mixed backmixing reaction chamber internal volume whileexpanding said tubular-flow reactor internal volume, and alternativeslideable movement of said bulkhead away from said housing portioncommensurately expands said injectively-mixed backmixing reactionchamber internal volume while diminishing said tubular-flow reactorinternal volume.
 7. The reactor system of claim 1 wherein saidinjectively-mixed backmixing reaction chamber has a first fluid inputand a second fluid input for said reactor system; said injectively-mixedbackmixing reaction chamber has a backmixing reaction chamber output;said tubular-flow reactor has a tubular-flow reactor input in fluidcommunication with said backmixing reaction chamber output; said firstfluid input receives a first fluid feed stream into saidinjectively-mixed backmixing reaction chamber; said second fluid inputreceives a second fluid feed stream into said injectively-mixedbackmixing reaction chamber; and said injectively-mixed backmixingreaction chamber has a space-time, respective to a combined feed rate ofsaid first fluid feed stream and said second fluid feed stream, of fromabout 0.05 seconds to about 1.5 seconds.
 8. The reactor system of claim1 wherein a first fluid stream in said fluid feed streams comprisesmethane and a second fluid stream in said fluid feed streams comprisesoxygen.
 9. The reactor system of claim 1 wherein at least one alkyloxygenate is manufactured through partial oxidation reacting of a firstfluid stream in said fluid feed streams comprising an alkane-containinggas feed stream and a second fluid stream in said fluid feed streamscomprising oxygen from an oxygen-containing gas feed stream; said alkaneis selected from the group consisting of methane, ethane, propane, andbutane; said injectively-mixed backmixing reaction chamber has an alkanegas input, an oxygen gas input, and a backmixing reaction chamberoutput; said tubular-flow reactor has an tubular-flow reactor input influid communication with said backmixing reaction chamber output; saidalkane gas input receives said alkane-containing gas feed stream intosaid injectively-mixed backmixing reaction chamber; said oxygen gasinput receives said oxygen-containing gas feed stream into saidinjectively-mixed backmixing reaction chamber; and saidinjectively-mixed backmixing reaction chamber has a space-time,respective to a combined feed rate of said alkane-containing gas feedstream and said oxygen-containing gas feed stream, sufficient forinduction of alkyl free radicals from said alkane within saidinjectively-mixed backmixing reaction chamber and for providing at leasta portion of said alkyl free radicals to said tubular-flow reactorinput.
 10. The apparatus of claim 9 wherein said alkane comprisesmethane and said alkyl oxygenate comprises methanol.
 11. The apparatusof claim 10 wherein said alkyl oxygenate further comprises formaldehyde.12. The apparatus of claim 9 wherein said alkyl oxygenate comprisesethanol.
 13. The apparatus of claim 9 wherein said alkane gas input andsaid oxygen gas input are configured to turbulently agitate saidinjectively-mixed backmixing reaction chamber by injective intermixingof said alkane-containing gas feed stream and said oxygen-containing gasfeed stream.
 14. The apparatus of claim 1 wherein said tubular-flowreactor has a tubular-flow reactor output, and said tubular-flow reactorhas at least one cooling gas input disposed between said tubular-flowreactor input and said tubular-flow reactor output for receiving acooling gas stream and thereby quenchably cooling said tubular-flowreactor.
 15. The apparatus of claim 9 wherein said tubular-flow reactorhas an axis, and said cooling gas input is moveable along said axisduring operation of said tubular-flow reactor.
 16. The apparatus ofclaim 1 wherein said injectively-mixed backmixing reaction chamber hasan internal volume defined in part by a cylindrical surface having aninjectively-mixed backmixing reaction chamber axis, and one feed streamof said feed streams is input into said internal volume from a pluralityof apertures disposed along said axis and in non-parallel orientation tosaid axis.
 17. The apparatus of claim 14 wherein said injectively-mixedbackmixing reaction chamber has an internal flow diverter defined by aconical surface having an axis, said diverter defines a conical base atone end of said axis, said conical surface defines an apexial end at theother end of said axis, said axis of said diverter is aligned with saidaxis of said injectively-mixed backmixing reaction chamber, saiddiverter is disposed within said housing such that said backmixingreaction chamber output is more proximate to said apexial end than tosaid conical base, and one feed stream of said feed streams is inputinto said internal flow space from a plurality of apertures disposedalong said injectively-mixed backmixing reaction chamber axis and innon-parallel orientation to said injectively-mixed backmixing reactionchamber axis.
 18. The reactor system of claim 5 wherein said bulkheadhas at least one passageway for fluid communication of aninjectively-mixed backmixing reaction chamber product stream from saidinjectively-mixed backmixing reaction chamber into said tubular-flowreactor, said tubular-flow reactor has a tubular-flow reactor input influid communication with said backmixing reaction chamber output, saidbulkhead provides said passageway with at least one aperture having across-sectional area, said tubular-flow reactor housing has an axis anda first portion and a second portion in threaded attachment to saidbackmixing reaction chamber housing, and said reactor system furthercomprises: a blocking component for variably obstructing a portion ofsaid cross-sectional area from passageway use during real-time operationof said reactor system; and a variable cooling gas input disposed insaid second portion in spiral orientation along said axis for quenchablycooling said tubular-flow reactor with a cooling gas stream; whereinsaid tubular-flow reactor housing second portion is in threadedattachment to said backmixing reaction chamber housing with threads thatmove said second portion along said axis when said second portion isrotated, and rotation of said second portion simultaneously repositionssaid bulkhead along said axis, said cooling gas input along said axis,and said blocking component to modify said cross-sectional area.
 19. Areactor system for gas phase reacting of at least two fluid feed streamsinto a product stream, said reactor system comprising: aninjectively-mixed backmixing reaction chamber in fluid communicationwith a tubular-flow reactor, said injectively-mixed backmixing reactionchamber having an internal volume defined by an internal surface of ahousing and a surface of a component in moveably sealed interface tosaid internal surface; and means for modifying said internal volume;wherein said means for modifying said internal volume moves saidcomponent to thereby modify said internal volume from a first internalvolume to a second internal volume.
 20. The system of claim 19 whereinsaid means for modifying said internal volume comprises a bulkhead inslideably-sealed interface to said housing; said housing has a housingportion in opposite disposition to said bulkhead; and said bulkhead isslideably movable to progress within said housing toward said housingportion to thereby commensurately diminish said internal volume, andsaid bulkhead is alternatively slideably movable within said housing toretract away from said housing portion to thereby commensurately expandsaid internal volume.